The present invention relates to SQL type query systems.
Data streams such as stock quotes, and the like can be stored in a database then analyzed using queries, such as SQL queries. For the data originated in the form of streams and to be analyzed in real time, some SQL queries, especially those using the join operation, can be quite problematic. In a conventional join operation, each data point from each stream must be compared to find the intersection of the two data sets. This works fine, since the datasets are bounded. But for data streams, datasets are unbounded and may require unbounded amount of memory.